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The Chemistry of Love: Umami, Aromas, and Fat

The flat, car-dotted landscape between Wharton Street and East Passyunk Avenue in south Philadelphia is scorched by the sun. Its hot, its humid, its loud with traffic. It is also the center of Phillys cheesesteak kingdom, a small patch of the city where all the best cheesesteak restaurants are located. There is so much steak grilled around here that the air itself smells of beef.

Im here because Im going to eat meat—for the sake of science. I feel guilty about the fact that Im about to swallow a small part of what once was a living, breathing cow, but I am also quite excited: the cheesesteaks are internationally famous as among the best meat-based dishes America has to offer, and I am here to find out what makes cheesesteaks, and meat in general, so appetizing.

Pats King of Steaks is a simple sandwich place with a clutter of red tables and benches that spill onto a sidewalk. It was founded in the 1930s by Pat Olivieri, who claimed to have invented the first ever Philly cheesesteak—a mouthwatering combination of melted cheese on thinly shaved grilled meat in a soft bread roll. President Obama ate here, and so did Senator John F. Kerry, as well as a plentitude of celebrities, whose pictures now line the walls.

Today, there is a long line of customers, each ordering swiftly and with confidence, wit onions and wit cheese (wit means “with” in Philadelphese). When I take a big bite of my sandwich, the full-bodied flavor of beef instantly fills my mouth. The meat is fatty, packed with aromas. Its good, very good. I can truly see (or rather taste) what all the fuss is about. Theres something about the flavor of cheesesteaks that can be truly enticing, even to someone who doesnt eat meat.

When prisoners on death row in the US ask for their last meals, their most common request is, by far, for meat. Studies show that 74 percent of American men and 61 percent of women crave meat the way others crave chocolate or ice cream. Weve long known why ice cream and chocolate appeal so much to our palates: its that blissful mixture of sugar and fat. But whats so special about meat that makes our taste buds beg for more? What is it about bacon and steak that attracts us, despite the growing pile of scientific data on meats detrimental health effects (think cancer, heart disease, type 2 diabetes)?

When I mention my cheesesteak experience to Gary Beauchamp, professor of biopsychology and an expert on taste perception, he actually chuckles. “Oh, yes, cheesesteaks. These are so good,” he says. Beauchamp is the former director of the Monell Chemical Senses Center in Philadelphia, where a good chunk of the worlds research on taste and smell takes place. Its the same institution that houses Paul Breslins fruit-fly lab. Thats not a mere coincidence. Although the low-ceilinged labs of Monell have a rather 70s-like feel, the research that is being conducted in here is very twenty-first century. The names of the scientists that adorn office doors and are scribbled on chemical vials and on the cages of lab mice (to make sure no one messes with other peoples work) are the same ones that constantly pop up on the front pages of science sections in newspapers and magazines.

Beauchamp’s office on the first floor is cheerfully cluttered with all the usual cliché scientific paraphernalia: papers stacked high on the desk, cardboard boxes full of jars, ethnic masks hanging on the walls. Beauchamp himself looks like the stereotype of a distinguished scientist: hes slim, silver bearded, and soft smiled. And he loves talking about research.

When I ask him what makes meat so attractive to our taste buds, Beauchamp thinks for a while, then replies: “Its not just one thing but a combination of things. Meat is rich in umami; it has a lot of fat. And this umami and fat combination seems to be a highly interactive one.”

Beauchamp believes that the key is meats unique mixture of umami and fat that gets spiced up when meat gets browned during cooking—a process called the Maillard reaction that produces particularly desirable flavors and aromas. How you perceive this mixture, though, depends on your genes, your sense of smell, and the number of tiny, mushroom-like structures on your tongue called fungiform papillae, on which taste buds are perched.

We can detect five basic tastes: salty, sour, bitter, sweet, and umami. Some scientists argue, with growing success, that we can also detect the taste of fat, while other researchers (with less success) are trying to prove the existence of calcium or metallic tastes. Some even say we may be able to perceive such tastes as electric and soapy, but data on that are very thin. What we do know is that the tongue or taste map that originated in 1901, which you may have stumbled across in old science textbooks, is incorrect. According to that map, we are able to detect specific tastes only in specific regions of our tongues. That is not true; in fact, all tastes can be detected almost anywhere on your tongue. It happens like this: you slide a piece of food (a slice of bacon, say) into your mouth. The saliva moisturizes the food and helps release the molecules of substances that evoke tastes, such as sodium chloride, which is responsible for the salty taste, or monosodium glutamate (MSG) for umami. These molecules then float toward your taste buds and bind to specific receptors on their surfaces. Later, three main nerves in the head called cranial nerves carry the taste messages to your brain, which make you either cringe with disgust or crave for more. Bitter and sour tastes are generally a warning that the food in your mouth may be poisonous or spoiled. Sweet means full of carbohydrates and calories (good), salty means sodium (necessary for proper functioning of our bodies), and umami most likely means proteins.

When it comes to perceiving flavors—responding to the tastes, textures, and aromas of foods—we are not all created equal. We have different densities of fungiform papillae and, as a result, different numbers of taste buds. Some of us have only two thousand in total; some have as many as eight thousand.

The discovery of why the number of our fungiform papillae matters to our taste perception is a rather recent one and dates back to a puzzling laboratory episode in 1931. It was then that Arthur Fox, a scientist working for DuPont chemical company in Wilmington, Delaware, accidentally spilled a substance called phenylthiocarbamide (PTC) in his lab. When his colleague, C. R. Noller, complained about the awful-tasting stuff floating in the air, Fox was puzzled—he couldnt smell anything, much less taste it. To prove Noller wrong, he put some of the white powder on his tongue—and found that to him it had no taste whatsoever. This exchange prompted Fox to study the taste of PTC. Soon he discovered that while some people, like Noller, find the substance unbearably bitter, others, like himself, cant detect any flavor at all in the powder. Fox calculated that about 28 percent of people cant taste the bitterness of PTC. What Fox didnt manage to do is figure out why some of us are supersensitive to PTC and some of us arent. It was Linda Bartoshuk, professor of otolaryngology at the University of Florida, who finally solved this mystery, over sixty years later.

Bartoshuk, who wears her hair short and her eyeglasses big, became a taste researcher because of her father. “He had lung cancer when I was in college, and one of the things that bothered him the most was that his taste changed,” Bartoshuk tells me over the phone in her strong, confident voice. “My aunt, his sister, made him a special kind of canned beef, hoping it would make him feel happier. But it tasted bad to him, metallic. It was bizarre. I realized only years later, when someone asked me why I study taste, that I have worked to solve this particular puzzle ever since.”

But before she managed to find out how cancer changes our palates, Bartoshuk ended up solving the puzzle of Foxs PTC tasters. She started noticing that no matter whether she studied the strength of bitter, sour, or sweet taste perception, the same people always scored the highest. One day she asked her colleague, an anatomist, to come over to her lab to look at the tongues of the high scorers. “He was stunned,” she recalls. “He said he had never seen tongues like that before.” What her colleague noticed was that these supertasters (as Bartoshuk calls them) have more fungiform papillae and, as a result, a higher density of taste buds than do either medium tasters or nontasters.

If you want to find out whether or not you are a supertaster, Bartoshuk recommends a simple experiment: apply blue food coloring to the tip of your tongue and press a one-quarter-inch-diameter hole punch reinforcement label onto the tip. Then, looking in a mirror, count how many pink bumps are visible within the ring reinforcement; or ask a friend to count the bumps, using a magnifying glass. These are your fungiform papillae. The blue food coloring wont stain them, so they will look lighter in color than the rest of the tongue and can be seen quite easily. If you have thirty-five or more, you are likely to be a supertaster. And whether or not you are a supertaster has significant implications for the way you perceive taste. It may even affect how much you like the taste of meat.

My own counting experiment, just as I expected, proved I was a nontaster. I had only ten fungiform papillae inside the reinforcement label. Why did I suspect all along I was a nontaster? The signs were many. Nontasters, like myself, are not only much less sensitive to bitterness in foods than others but also more tolerant of oral pain, including spiciness. (Spiciness is not a taste, Bartoshuk tells me. Its a type of pain sensation.) Nontasters tend to like their coffee black and dont mind tannins in their red wine. They also tend to eat more vegetables of various kinds than do supertasters. The problem that supertasters have with veggies is that many of them contain bitter compounds called phytochemicals, which may act as natural pesticides, protecting the plant from parasites and predators. Beans, cabbage, brussels sprouts, zucchini, lettuce, grapefruit—the list of veggies and fruits loaded with bitter compounds is long. If you are a nontaster, you can happily enjoy such nutritious meat substitutes as dal or hummus, but if your taste buds are particularly plentiful, a vegetarian diet may be more of an uphill struggle for you. It doesnt mean, though, that you should just give up on bitter veggies altogether. Bitter phytochemicals such as phenolic compounds or flavonoids found in vegetables are actually very healthy. They lower the risk of cardiovascular disease and several types of cancer, may help cure some immune disorders, and help manage type 1 diabetes.

Yet although being a bitter-sensitive supertaster sounds like a perfect explanation for why some people may be slow to reach for healthy veggies and are hooked on meat, its not so clear-cut. Some studies do show that supertasters eat less spinach and broccoli and like meats more than nontasters do, but other experiments report that instead of substituting bitter foods with animal protein, supertasters tend to gorge themselves on sweets. According to Bartoshuk, supertasters are more likely to be extreme about both sugar and meat, since in general they are more intense in their responses to food, strongly craving their favorite foods, while intensely disliking their least favorite foods.

 

Yet perceiving tastes is only a small part of what is going on in your mouth as you eat. You may notice creaminess, crunchiness, or sogginess—those are textures, detected by specialized neurons. In your slice of bacon, you may detect grassy notes or a hint of nuts and earth—those are aromas. As you chew, volatile compounds are released and drift up your throat toward your nose to be registered in a process called “mouth smelling.” A large chunk of what we think of as meats taste is actually its aroma.

The lack of strong aromas is one of the main reasons why we dont find raw meat very appealing. Even animals seem to agree: when scientists offer lab mice roasted ministeaks, for example, at first the animals are rather wary of this culinary invention. After a few bites, though, they go crazy for the cooked beef. In similar experiments, chimps, gorillas, and orangutans are clear about their preferences: roasting, grilling, and stewing make meat delicious. And one of the main reasons for that is the aforementioned Maillard reaction, the marriage between carbohydrates and amino acids in a slightly moist, hot environment (between 300 and 500 degrees Fahrenheit), which produces aromas so delightful they make us go weak in the knees.

Louis-Camille Maillard, the doctor who discovered this reaction back in 1912, looked like a hipster by modern standards, with his gelled hair, ultratiny round spectacles, and pointy mustache. Of course, in early twentieth-century France, where he lived and worked, this style was quite common.

Although Maillards name is now practically synonymous with one of the most important reactions in food processing, the young physician wasnt originally interested in finding out why some foods taste delicious when they brown up. He was interested in kidney diseases. One day when he was heating sugars and amino acids together in a test tube, he noticed with surprise that the mixture turned brown at a lower temperature than expected. Maillard continued to study the reaction and in 1912 presented his findings to the French Academy of Sciences. But he failed to realize its gastronomical implications: he thought his discovery was mostly important for human physiology and for understanding coal and manure. Only later did he begin to see that the reaction he described was behind our love of some foods.

There are over one thousand substances responsible for the aromas of meats, and many are created in the Maillard reaction. Some smell fruity (γ-heptalactone), others musty (trimethyl-pyrazine), while still others may have the scent of nuts, mildew, smoke, marshmallows, or even crushed bugs (3-Octen-2-one). Although by themselves they may seem unappealing, taken together these substances comprise the mouthwatering aromas of meats. Protein hunger researcher Breslin jokes that even God appears to delight in the scents of the Maillard reaction. There are several passages in the Bible, he tells me, that mention how animal sacrifices as burnt offerings bring out “an aroma pleasing to the Lord.” Why are we so attracted to these scents? One explanation is that in prerefrigeration times meats got easily spoiled by bacteria, and the Maillard reaction was a way for us to notice that the food had been cooked and was safe to eat.

But there is a darker side to the Maillard reaction: it can produce acrylamide, a probable carcinogen, which forms when the amino acid asparagine (found in dairy products, beef, poultry, and eggs) is combined with glucose. Other products of the Maillard reaction have been associated with the development of diabetes, kidney problems, and cardiovascular disease. It seems that although the pleasing aromas of the Maillard reaction might have guided our ancestors toward safe and nutritious foods, in our age of refrigerators and antimicrobials, we should be less trusting of these tempting scents. Especially if we want to live past the age of thirty-five, the average life span of our Paleolithic, Maillard-reaction-loving ancestors.

 

Fat is another big piece in the puzzle of meats delicious flavor. It is more energy dense than sugars and, as such, is highly desirable. For our ancestorssurvival, it was vital that they identify and feast on foods loaded with fats, whenever they were available. After all, overindulging in very lean meat (the condition of most animals on the African savanna during the dry season) could lead to “rabbit starvation” and death.

It appears that human bodies just dont react well to diets in which over 35 percent of the calories come from protein—we need fat to dilute it. The lure of meats fat is mostly in its aromas—all those sweet, charred, mouthwatering smells that waft out of the restaurant kitchens between Wharton Street and East Passyunk Avenue in south Philadelphia and which tempted me to buy a cheesesteak. But according to Breslin, instead of straying from the vegetarian path, I could have probably made my taste buds and brain happy with a serving of ice cream or something else that is fatty and tasty. “When you think youre craving meat, most likely what youre really craving is tasty fat. If you ate something that had almost no fat in it—a well-trimmed, lean piece of meat—it might not satisfy the craving. Hypothetically, though, a bowl of fatty ice cream could,” he explains. When you cook a piece of pork or beef, its not just the Maillard reaction that occurs. Fats start to oxidize, and even more delicious scents rush toward your nose. Fat is also where the most significant differences between the flavors of different species lie. Boiled or stewed beef smells mostly of an aldehyde called 12-methyltridecanal, which gives beef its unique tallowy and slightly sweet aroma. Another potent compound of the scent of beef is 2-methyl-3-furanthiol, which scientists describe as smelling sulphurous, sweet, and “vitamin.” Chicken, meanwhile, smells of trans-2-trans-4-decadienal, which at low concentrations has an aroma of oranges or grapefruits.

Yet its not just the smell of fat that keeps us hooked on meat. Its the texture, too: creaminess, juiciness, and crunchiness are all sensations that tell us that the meat is loaded with fats. Neural-imaging studies show that specialized fat-sensitive neurons in the brain respond to the lubricity (slipperiness) of fat in our mouths, which registers as a pleasurable experience. Whats more, over the last ten years evidence has been mounting that we can detect the taste of fat in our mouths, in a similar way that we taste salty or sweet—which would make fat the sixth basic taste. This detector system informs our brains that fat is present in the food and can prepare the body to digest it, as well as reward us with pleasure for eating it. Painting your tongue blue can also give you an insight into how well you detect fat in foods. The more mushroom-like fungiform papillae you have, the better your ability to detect fat in some foods, studies show. For example, supertasters may excel at telling whole milk from a low-fat one. But nontasters have their own ways of responding favorably to fat: experiments show that nontasters prefer their food high in fat, since they are so inept at perceiving it at low concentrations.

But not all fat in meat tastes equally good. Imagine you got magically transported back in time into the depths of the Mesozoic era, into a towering forest full of ferns and gingko plants. You conveniently have brought with you an impressively big shotgun. You are starving. You need to find some food ASAP. Yet there are no familiar species of animals that could give you an idea of what to hunt. As you look around, you notice a few dinosaurs of different species grazing or walking around. Assuming they would all require similar skill and effort to hunt, which one should you kill? Which of the dinosaurs would make for the best steak? A Tyrannosaurus rex? One of the long-necked sauropods—the largest animals to ever walk the earth? Or maybe an ostrich-like ornithomimid—one of the fastest runners of the dinosaursworld?

The secret to the tastiness of an animals meat lies to a large extent in its diet, which translates into the composition and flavor of its fat. The majority of people around the world prefer meat that comes from herbivorous animals, such as cows, sheep, or deer, since a carnivores diet adds a gamey flavor to the animals fat that is not very appetizing. Thats one of the reasons why lion burgers and cat steaks are not exactly popular and also why the meat of a T. rex likely wouldnt be very tasty. Youd be better off hunting the ornithomimid. Because of its very active lifestyle (ornithomimids ran a lot), that particular dinosaurs meat would be composed of slow-twitch muscle fibers, which means it would be red, a bit like beef. The high activity levels of ornithomimids would also mean that their flesh would be quite rich in umami—the fifth basic taste, which is the last clue to why humans love the taste of meat.

 

It took a Japanese chemist named Kikunae Ikeda just a little over a year to figure out what tomatoes, meat, and kombu kelp have in common. In Kyoto, where Ikeda was born in 1864, kombu was commonly used to make a broth called dashi, which in turn served as the base for miso soups and noodle dishes. Ikeda, a slim, frail-looking man, noticed that dashi has a very distinct taste, quite different from salty, sweet, bitter, or sour. He also noticed that whenever his wife cooked soups based on dashi, they were particularly delicious. One day in 1907, Ikeda (who by then was a professor of chemistry at Tokyo Imperial University) took a huge evaporating dish, filled it with water and eighty-four pounds of dried kombu, and let it all simmer. From the broth he obtained, he managed to extract one ounce of monosodium glutamate, which is the sodium salt of an amino acid glutamate. That was it. Ikeda was convinced that monosodium glutamate gave the specific taste that was behind the deliciousness of not just dashi but also of tomatoes, cheese, and meat. He called this new taste umami—Japanese for “delicious.”

Unlike Maillard, Ikeda knew right away that what he had discovered not only was fundamental for science but also had practical applications for the food industry. He quickly obtained a patent for a seasoning based on monosodium glutamate and contracted Saburosuke Suzuki, a businessman who worked in iodine production. Suzuki was impressed with Ikedas discovery and decided to invest in it. Soon Suzuki Pharmaceutical Company started to manufacture and market monosodium glutamate under the name Ajinomoto, Japanese for “quintessence of flavor.” Today, Ajinomoto Company is a major Japanese corporation and operates in twenty-six countries. It sells 40 percent of the worlds aspartame sweetener and is the largest producer of MSG (monosodium glutamate) seasoning on the planet. If you go to your nearest well-stocked grocery store to buy MSG, it will most likely come in the characteristic red Ajinomoto packaging.

From the beginning, though, Western scientists were skeptical of Ikedas discovery. So skeptical that it took almost a century for “deliciousness” to become widely accepted as the fifth basic taste. Most Western scientists believed umami to be no more than a combination of the other four tastes and claimed that re-creating umami is just a matter of finding the exact proportions of salty, sweet, sour, and bitter. Yet no one ever managed to achieve that—and not for want of trying. It was only in 2000 that umami finally got its big break. That year three American scientists located umami receptors on human tongues, a discovery that was soon confirmed by other researchers. Umami officially entered the pantheon of basic tastes.

In nature, three substances are responsible for umami taste: amino acid glutamate (which is behind the deliciousness of Parmesan cheese, soy sauce, sun-dried tomatoes, and cured meats) and two nucleotides—inosinate (IMP), found in meat and fish, and guanylate (GMP), present mostly in mushrooms. When one or both of these nucleotides are combined with glutamate, the umami taste of a dish is magnified to as much as eight times that of glutamate alone. This synergy is why pepperoni pizza and Pats Philly cheesesteaks are so mouthwateringly delicious—its the glutamate from cheese, plus IMP-rich meat and GMP from mushrooms (as long as you order your cheesesteak “wit” mushrooms, of course). Meat is a particularly good example of umamis mouthwatering synergy: because it contains the umami compounds glutamate and inosinate, it produces a strong and long-lasting “delicious” sensation.

All this is no secret to the best chefs—some of whom call dishes that profit from the umami synergy “u-bombs” and who eagerly use these substances in their cooking. Adam Fleischman, the chef of the famed Umami Burger restaurant in Los Angeles, named his signature umami burger umami × 6.” It maximizes the delicious umami sensation by combining beef with grilled shiitake mushrooms, roasted tomato, caramelized onion, homemade ketchup, and pan-fried Parmesan. Another celebrated chef, Sat Bains, who heads the kitchen of a Michelin-starred restaurant in Nottingham, UK, creates a delicious “u-bomb” by brining beef overnight in a kombu solution, to benefit from the synergy of the inosinate in meat and the glutamate in the seaweed.

Humans love umami. We learn its taste even in utero (the amniotic fluid contains glutamate) and then at mothers breast, as human milk is particularly rich in umami, much richer than that of most other mammals. Yet many of us in the West have trouble telling umami taste as easily as we can pinpoint sweet or salty. You wont hear many Americans or British say: “Oh, that soup is not umami enough.” So what does umami actually taste like? To find out, try an experiment recommended to me by Beauchamp during my visit at Monell. Take two cups of soup. To one of them add a sprinkle of MSG, which you can buy in most well-stocked grocery stores. Take a sip of each soup and compare—the difference should be obvious. When I did this experiment, I knew right away which soup had MSG in it. It tasted much fuller than the other one, more savory and round. It tasted “meaty,” as umami is often described, even though there was no meat in the soup. I could feel the umami taste not only on my tongue but all around my mouth—on my palate, on the insides of my cheeks. Did it taste better? You bet.

If the soup experiment doesnt help you pinpoint umami, you may be umami blind. About 3.5 percent of the population are unable to detect the umami taste of monosodium glutamate. Meanwhile, a study of twins showed that our liking of protein foods such as meat and fish is the most heritable of all food preferences. The reason may lie in the way we respond to umami and that some of us are genetically better at discriminating this particular taste. Other experiments point in the same direction: people who are the most sensitive to the taste of MSG report a greater liking and preference for protein-rich foods, like meats. Could that mean that the 3.5 percent of us who are insensitive to umami are more likely to become vegetarians? And is it just a mere coincidence that in many Western countries the percentage of vegetarians oscillates around 3.5 percent? Maybe thats all it is—a coincidence. Maybe not. So far there have been no studies that examine how insensitivity to MSG may translate into choosing a vegetarian diet. If you know any academics doing research on nutrition, ask them. Maybe that question will spike their interest enough to investigate.

There are some vegetarians out there, though, who stick to their diets precisely because of their inability to taste umami. Although giant pandas (these are the vegetarians Im talking about) officially belong to the order Carnivora, along with such avid meat eaters as lions and wolves, they are basically vegetarians. Their diet is 99 percent composed of everything bamboo: bamboo leaves, shoots, and stems. In one year a single panda devours over ten thousand pounds of bamboo. The remaining 1 percent of the giant panda’s diet comes from such bamboo seasonings as grasses, bulbs, and insects. The thing about giant pandas is that although they have the short digestive system of a carnivore, their umami taste receptor gene is not functional, and as a result, giant pandas can’t taste umami. The loss of the umami perception may explain why giant pandas are not interested in meat anymore. Over generations, their decreased reliance on meat could have resulted in their loss of umami taste receptors, which helped to keep the animals hooked on bamboo. Since pandas couldnt taste umami anymore, they stopped liking meat and eating it.

Why does umami taste so delicious to us? Why do we seek out foods that, just like cooked meat, are brimming with umami? Most scientists believe that umami signals the presence of proteins in foods and helps us choose good sources of that nutrient. Meat, of course, is rich in proteins. But umami is not just about proteins—it could also mean that fewer harmful bacteria are present. Cooking and aging break down large protein molecules in meats and release glutamate, making foods more umami. Umami taste, just like the products of the Maillard reaction, may signal that the meat has been cooked—and is safer to eat. But there is still a lot of mystery surrounding umami. We dont know why human milk is so loaded with it. We are not sure which genes can make humans umami blind. We don’t know the purpose of umami in tomatoes, since they are not exactly brimming with proteins. “What we do know,” Beauchamp tells me in his cluttered Indiana Jones–like office, “and thats something Im very convinced about, is that umami is a particularly potent enhancer of pleasure in certain foods, including meat.” And if you cant taste umami, bacon, burgers, and cheesesteaks wont be as yummy to you as they are to others.

 

Are we then doomed to crave beef and chicken and pork, with their delicious umami, mouthwatering fat, and aromatic products of the Maillard reaction? Are we going to stay hooked on meat no matter how bad all these cheesesteaks and burgers may be for our arteries and for the planet? After all, even many vegetarians are not immune to the lure of meats flavors. According to one survey, 60 percent of vegetarians admitted to having eaten meat within the past twenty-four hours.

But knowing what precisely makes meat so delicious and enticing—which exact aromas and umami substances and which fat textures—can help in the future to create the perfect meat substitute, the vegetarian Holy Grail. There is still a lot of work left for scientists to do, of course. Out of at least a thousand substances that create meat aromas, we know only a few. We dont understand the perception of fats very well. We dont know exactly how umami works and why some people are blind to it. There are many studies and experiments to be done. It requires time.

Years of evolution have taught us to seek out cooked meat for the nutrition it offers. We are genetically programmed to respond favorably to umami, which signals the presence of proteins, and to the aroma of cooked meat (the Maillard reaction), which signals that the food is safe to eat. Of course, it does not mean we should just follow our taste buds blindly and munch beef burgers like pandas munch bamboo. The meats of today are not the same as the meats of the past. Our lifestyles have changed. The way we rear animals has changed and so have our bodies—even if our taste genes lag behind. Who knows: maybe they will also adjust one day and make our palettes better suited to the modern world. But we dont have to wait for a panda-like mutation in our taste genes to occur. We can use the knowledge about what makes meat delicious to replicate these sensations with other foods that are better for our health and for the environment. Those who want to cut down on meat can try a few simple tricks. For your Maillard reaction fix, choose freshly baked breads, crunchy toasts, and roasted veggies. To make up for fats in meat, go for avocados, cheese, and nuts. As for umami, try tofu cooked with soy sauce, a little peanut butter, and mushrooms. Even if these foods dont exactly taste like grilled steak, they can still make your taste buds very happy.

Yet such culinary tricks wont delight everyone—not the meat industry, for one. After all, the industry works hard to ensure that we will like the taste of meat more than the taste of its substitutes: animals are bred, fed, and killed in ways that win the battle for our palates and our wallets. Meat producers massage cows with sake, feed green tea to chickens, castrate baby pigs (with no anesthesia), and inject meat with brine—all the while struggling to keep a perfect balance between the taste of meat and its cost so that we keep coming back for more and more and more.